Use a square of paper.

1 Valley fold the lower sloping edges to meet the central line.

2 Valley fold the bottom corner as shown.

3 Open out the flaps.

4 Valley fold the upper sloping edges to meet the central line.

5 Valley fold the top corner as shown.

6 Valley fold the corner as shown.

7 Valley fold the corner as shown.

8 Mountain fold the lower sloping edges to meet the central line.

9 Valley fold the upper sloping edges to meet the central line. Unfold them.

10 Make the creases

11 Fold over and over the tip of the corner into the pocket.

12 The result. Turn the model over.

13Mountain fold the corners as shown.

14 Valley fold the bottom corner.

15 Insert the corner's tip into the pocket.

16 Turn the model over and around...

17 and Case is ready!

It can be dressed on a belt and to carry in it small flat subjects. For example, sheets for origami.